Question

Which of the following traits is not shared by both sea anemones and jelly fish?

• A. A medusa as the dominant stage in the life cycle
• B. Possesion of gastro vascular cavity
• C. Diploblastic
• D. Nematocysts on the tentacles

Answer 1

The correct option is A A medusa as the dominant stage in the life cycle

Sea anemone and jellyfish are the members of phylum Cnidaria. The life cycle of most cnidarians have two different forms - medusa and polyp. The free swimming sexual form is called the medusa and the asexual form is called the polyp. Jellyfish has both medusa and polyp stage in their life cycle, but the sea anemone has lost the medusa stage and spends the life cycle as polyp.
Cnidarians have specialised cells called cnidocytes. These cnidocytes consists of an organelle called the nematocyst. The stinging property of cnidarians is due to the secretion of nematocyst.
Most of the Cnidarians lack mesoderm, thus they are diploblastic. They also possess a gastrovascular cavity which is responsible for digestion and circulation.